Fullerene is a soccer-ball-shaped molecule which consists of an arrangement of carbon atoms with a hollow inside. As a conventional carbon Fullerene superconducting material, alkali-doped C60 Fullerene molecules are known to exert superconductivity. An oxide superconductor is also known as a high-temperature superconducting material.
However, superconducting transition temperature of such an alkali-doped C60 Fullerene molecule is as low as 40K at maximum, rendering it unpractical for use under a relatively high temperature. An oxide superconductor that exerts superconductivity at the temperature of liquefied nitrogen is poor in chemical stability and thus is not quite appropriate to be used in an electric circuit material that requires fine fabrication. Other superconducting material consisting of carbon Fullerene molecules smaller than C60 molecules has not been achieved.
Thus, the present invention has an objective of providing a superconducting material in which C20 Fullerene molecules are polymerized into a one-dimensional chain, where bonding portions between C20 Fullerene molecules are bound via a SP3-bond form, or no sp3-bond is contained other than at the bonding portions between C20 Fullerene molecules, or where the superconducting material is obtained by injection of electrons or positive holes.